Stable anti-perspirant stick



United States Patent STABLE ANTI-PERSPIRANT STICK W Kedzie Teller, Riverside, and Elmer B. Tysdal, Batavia, 111., assignors to Pharma-Craft Company, a division of Joseph E. Seagram & Sons, Inc, a corporation of Indiana No Drawing. Application December 10, 1956 Serial No. 627,125

4 Claims. (Cl. 167-=-9i)) This invention relates toan improved perspiration inhibiting material and more particularly to such material in the form of a soap gel stick which contains sodium stearate, isopropyl myristate and/or isopropyl palmitate, and aqueous alcohol having distributed therein aluminum hydroxide gel as the perspiration inhibiting substance.

This invention contemplates incorporating comparatively low proportions of isopropyl myristate and/or isopropyl palmitate into a soap gel stick which contains a sodium stearate-aqueous alcohol gel base having aluminum hydroxide gel dispersed therein so as to impart enhanced physical stability to the stick without necessitating the aging of freshly prepared sticks. Thus, these esters enable a freshly preparedstick to be pushed in and out of a dispenser unit such as shown in copending Teller and Bernhardt application Serial No. 477,312, filed December 23, 1954, without crumbling.

Sodiumstearate soap gel sticks have heretofore been known for various cosmetic purposes. These sticks are stable at normal atmospheric temperature ranges within certain known proportions of sodium stearate, alcohol and water. They are extremely desirable inasmuch as on contact with the skin, they have a pleasant cooling cfi'ect and do not leave a greasy or'waxy residue.

However, the sticks are extremely sensitive to chemical reaction. The provision of a metal ion in a form free to react with sodium stearate to produce another metallic stearate will render the stick unstable if that ion is present in any substantial quantity.

Because of this consideration, it has heretofore been considered impossible to produce an anti-perspirant soap gel stick sinceknown anti-perspirant chemicals include an ionizable form of a polyvalent metal, as for example, aluminum'chloride.

The introduction of such a material'into a soap gel stick of the form heretofore described results within a comparatively short time in a breakdown of the stick. This breakdown normally involves a loss of the stick form either by the forming of a mush or by formation of a multiphase system.

Aluminum hydrate gel, in spite of its nonacid character, has known remarkable high anti-perspirant qualities. When mixed with water and sodium stearate, however, a reaction occurs to form aluminum stearate. As pointed out in our copending application Serial No. 520; 918, filed Iuly.8, 1955, it has been discovered, however, that in spite of the normal ionic ability of the aluminum in aluminum hydroxide gel, when this material is enclosed in a sodium stearate gel stick, it does not so react and the stick is stable.

The precise reason for this lack of reaction is not known. It is presumably due to an ionization-depressing effect produced by the high concentrations of alcohol in the stick. It is not solely due to that factor, however, since other ingredients of the stick also appear to eifect or. add to this ionization depression. That is, the pro portions of sodium stearate and alcohol and water and its acceptance in products of this general type.

2,933,433 Patented Apr. 19, 1960 the aluminum hydroxide are all inter-related in this ionization depression.

One of the remarkable facts is, however, that so far as has been ascertained, the proportions of ingredients which will produce a stable sodium stearate stick coincide with the proportions which will sufiiciently depress ionization to permit incorporation of aluminum hydroxide as the anti-perspirant ingredient.

We have discovered that 1.5-6% by weight of isopropyl myristate and/or isopropyl palmitate may be effectively incorporated into our aluminum hydroxide gelcontaining soap gel stick when the ratio of sodium stearate to isopropyl myristate and/or isopropyl palmitate exceeds 1.75 to 1.

Aluminum hydroxide, Al(OH) is available in a form sometimes referred to as true aluminum hydroxide, wherein it is suspended in water in a concentration of about 10% aluminum oxide by weight. In this form it has a gel-like consistency. The gel may be dried to heavier consistencies and almost to apparent dryness to thetouch without removing any of the Water of combination by various well known techniques in which uncombined water is removed. In such dried form it still retains its identity as true aluminum hydroxide. In the following specifications and claims the aluminum hydroxide used in the practice of this invention will be identified as aluminum hydroxide gel since it may be used in any concentration with appropriate adjustment of quantities of other liquids and especially of water, which may be used. As is customary in connection with aluminum hydroxide in any such form the concentration or quantities thereof will be expressed in terms of aluminum oxide (A1 0 It is believed to be a particular advantage of our composition in that it affords a slightly alkaline stick-type product having both deodorant and anti-perspirant qualities. in contract with this, many of the anti-perspirant compositions available to the public are acid to a varying degree and none of them is in the form of a stick having a soap-gel base.

In the practice of the present invention a typical soap gel containing isopropyl myristate and/ or isopropyl palmitate may be formed and melted and a useful quantity of aluminum hydroxide gel may then be stirred into the melted gel. is stable when stored in a closed container and at normal room temperature. Also, the' ingredients of our soap gel may be mixed together at an elevated temperature, and useful quantities of aluminum hydroxide gel may thereafter be distributed therein. Upon cooling the soap gel will solidify apparently without any adverse effects flowing from the presence of the aluminum hydroxide. The resulting product is similarly stable. Also the composition may have incorporated therein moisture retaining substances and perfumes. Furthermore, in accordance with the examples set forth hereinbelow, a composition may be prepared with a soap gel and aluminum hydroxide gel in useful quantities to serve as anti-perspirant and, in addition, there may be incorporated recognized deodorant materials, for example, a dihydroxy halogenated diphenyl methane, such as the widely used hexachlorophene. The resultant stick-type productis similarly stable and exhibits unusual qualities for the reduction in quantity of perspiration as well as preventing the development of odor.

Ethyl alcohol is preferred as the alcohol because of Other suitable volatile alcoholsmay be used. For example, isopropyl or polyhydric alcohols or mixtures thereof with ethyl alcohol may be used and are to be included in the term alcohol employed in the following examples and claims. Also within the term alcohol is a mix- The resultant product, upon cooling,

ture of one or more-volatile alcohols with not more than an equal volume ofpropylene glycol. Water which may be present as a part of the aluminum hydroxide gel or which may be added in relatively small quantities will serve to control the rate of evaporation and thus toestablish the desired cooling effect when applied to the person. It is important for the product of this inven: tion that the soap gel consist primarily of soap and alcohol and it will be so described in the claims. The relative proportions between quantities of soap, alcohol and water, if the latter is used, are merely so chosen as to provide a final stick product having firmness and cooling efiect within relatively wide ranges of personal preference. The specified quantities of optional additives such as perfumes, deodorant materials or moisture retention agents of which Carbitol (diethyleneglycol ethylether) is an example, although preferred for practical reasons and suitabe for the particular material s named, are not critical to the present invention.

In the following examples a typical useful quantity of aluminum hydroxide gel will be set forth. It is believed that the range of quantity in which this substance may be added is limited only by practicality. That is to say, if only two parts by weight per hundred of the final product consist of aluminum hydroxide gel (10% A1 the anti-perspirant qualities would be very slight. However, useful anti-perspirant qualities are exhibited with as little as five parts per hundred and an exceedingiy elfective product-is achieved by the use of about ten parts per hundred. Increase in quantity above ten parts per hundred to about twenty parts per hundred does not sensibly increase the desired anti-perspirant eifect although it should be stated that such largerquantities bring about no unfavorable reaction upon the stability f the end product. 3 Accordingly, in the claims the quantity of aluminum hydroxide gel will not necessarily be stated in terms of precise proportions but rather will be setv forth as a useful quantity. 1

EXAMPLE I An anti-perspirant stick is prepared from the follow ing ingredients. Relative proportions are set forth as parts per hundred by weight.

Parts by weight Hexachlorophene 0.23 Alcohol 67.70 Sodium stearate 6.77 Carbitol l .3 5 Isopropyl myristate 1.81 Water 12.68 Aluminum hydroxide gel A1 0 9.05 Perfume 0.41

The alcohol, hexachlorophene, Carbitol, isopropyl myristate, sodium stearate and about one-half of the water may be mixed, heated to 70 C. and maintained at 70 C. until the sodiumstearate is completely dis solved. The other one-half 'of' the water is carefully added to the aluminum hydroxide gel while stirring to form a smooth mixture. The diluted aluminum hydroxide gel is then added to the mixture in which the sodium stearate is dissolved and the resultant mixture is stirred constantly for about fifteen minutes during which the temperature is permitted to drop to from 62 to 65.

The perfume is added just before pouring into molds. The final mixture is poured at the temperature of from 62' to 65 C. into cold (room temperature) molds. Preferably the molds are of size and shape toform a plurality of individual sticks which may be removed from the molds when cooled and packaged for sale. For example the individual sticks may be cylindrical in form and of a size suitable for convenient use. Furthermore, the product may be poured into molds consisting of elements of the package in which the product is to be sold as disclosed in copending application Serial No.

477,312, filed December 23, 1954, by Bernhardt and Teller.

The order in which the isopropyl myristate is added to the composition is not critical.

It is important that the mixture be stirred frequently or constantly after the aluminum hydroxide gel has been added and until the mixture has cooled to the temperature range set forth. In this manner the aluminum hydroxide gel is maintained thoroughly distributed in the mixture. Stirring may be continued during pouring for the same purpose. The product will harden quickly in the relatively cool molds due to solidification of the soap gel base. The finished product is stable and needs only to be packaged in an airtight fashion to prevent evaporation of the alcohol and water to have adequate shelf life for normal channels of distribution. The finished product has been subjected to extensive tests which amply demonstrate highly desirable antiperspirant and deodorant qualities.

' EXAMPLE II An anti-perspirant may be made from ingredients set forth in Example I except that isopropyl palmitate may be substituted for isopropyl myristate. The procedure may be the same as therein set forth. The final product has highly desirable anti-perspirant qualities.

EXAMPLE III The particular order of addition of the ingredients set forth in Examples I and II may be varied withoutapparent effect on the final product. Thus, the products of Examples I and II may be prepared by mixing the so-. dium stearate with the aluminum hydroxide gel and thereafter adding such mixture to the alcohol, isopropyl myristate and/or isopropyl palmitate, a-nd water. The optional ingredients such as moisture retention agents, deodorants and perfumes may be added in any order although it is preferred for economical reasons to add the perfume just before pouring. Preferably, for the purposes of this example, the aluminum hydroxide gel is in the form of a suspension in water in a concentration equivalent to 10% A1 0 and it may be further diluted with water before mixing ,with the sodium stearate to facilitate dissolution of the sodium stearate.

It is recognized, of course, that the term sodium. stearate is used-commercially to apply to. the sodium salt of a mixture of fatty acids of which stearic acid and palmitic acid predominate with-relatively small proportions of closely related fatty acids. The term is used here in its commercial sense. The alcohol referred to is preferably ethyl alcohol or isopropyl alcohol. I

Table I, infra, shows the indicated limits of the primary constituents of the sodium stearate soap gel stick.

isopropyl myristate or isopropyl palmitate 1.5-6

1 The ratio of sodium stearate to isopropyl myristate and/ or isopropyl palmitate should exceed 1.75 to 1.

Table II, infra, shows the preferred limits'of the primary constituents of our sodium stearate soap gel stick.

Tablell Percent by weight Alcohol 62-69 Water 12%1-17 Sodium stearate 6 5-9 6 Aluminum hydroxide gel (10% A1 0 5-13Vs Isopropyl myristate or isopropyl palmitate 1.5-6

1 The ratio of sodium stearate to isoprop 1 m ristate and or isopropyl palmitate should exceed 1.75 to 1? a H This application is a continuation-in-part of our copending application Serial No. 520,918, filed July 8, 1955, which in turn is a continuation-in-part of our copending application Serial No. 486,976, filed February 8, 1955, both now abandoned.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications will be obvious to those skilled in the art.

We claim:

7 1. A stable anti-perspirant stick comprising: a base having a sodium stearate-aqueous alcohol gel and, as a physical stabilizer, at least one member from the group consisting of isopropyl myristate and isopropyl palmitate; said base having about 412% by weight sodium stearatc, about 4-45% by Weight water, about 56-87% by Weight alcohol, and about 1.5-6% by Weight of said physical stabilizer wherein the Weight ratio of sodium stearate to stabilizer exceeds 1.75 to 1; and about 214% by weight aluminum hydroxide gel dispersed in said base as an active anti-perspirant agent. i

2. The stable anti-perspirant stick set forth in claim 1 wherein the physical stabilizer is isopropyl myristate.

3. The stable anti-perspirant stick set forth in claim 1 wherein the physical stabilizer is isopropyl palmitate.

4. A stable anti-perspirant stick comprising: a base having a sodium stearate-aqueous alcohol gel, an effective amount of aluminum hydroxide gel dispersed in said base as an active anti-perspirant agent and, as a physical stabilizer, about 1.5-6% by weight of at least one member from the group consisting of isopropyl myristate and isopropyl palmitate, the weight ratio of said sodiui'n stearate to said stabilizer exceeding 1.75 to 1.

References Cited in the file of this patent UNITED STATES PATENTS 2,087,162 Moore July 13, 1937 OTHER REFERENCES Pears: Perf. and Ess. Oil Record, 44:3, March 1953, pp. 8490.

144b, recd March 6, 1956, excerpts from bulletin (2 pp.).

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent Noa 2 933 433 April 19 1960 W Kedzie Teller et alta It is hereby certified that error appears in the-printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2 line 25, for "specifications" read specification 5 line 37 for "contract". read M contrast Y column 3, line 18 for "suitabe read suitable lines 28 and 29 for exceedingiy read exceedingly "e Signed and sealed this 11th day of April 1961.,

(SEAL) A H I rmieei.

ERNEST w. SWIDER ARTHUR W. CROCKER Atiestmg Uiiicer Acting Commissioner of Patents 

1. A STABLE ANTI-PERSPIRANT STICK COMPRISING: A BASE HAVING A SODIUM STEARATE-AQUEOUS ALCOHOL GEL AND, AS A PHYSICAL STABILIZER, AT LEAST ONE MEMBER FROM THE GROUP CONSISTING OF ISOPROPYL MYRISTATE AND ISOPROPYL PALMITATE, SAID BASE HAVING ABOUT 4-12% BY WEIGHT SODIUM STEARATE, ABOUT 4-45% BY WEIGHT WATER, ABOUT 56-87% BY WEIGHT ALCOHOL, AND ABOUT 1.5-6% BY WEIGHT OF SAID PHYSICAL STABILIZER WHEREIN THE WEIGHT RATIO OF SODIUM STEARTE TO STABILIZER EXCEEDS 1.75 TO 1, AND ABOUT 2-14% BY WEIGHT ALUMINUM HYDROXIDE GEL DISPERSED IN SAID BASE AS AN ACTIVE ANTI-PERSPIRANT AGENT. 